Magnetic clarifier



Feb. 28, 1956 A. w. GARDES MAGNETIC CLARIFIER 4 Sheets-Sheet 1 Filed Feb. 8, 1951 AZfrea I/l/T Gardes W MJ QMHZZ E Feb. 28, 1956 A. w. GARDES 2,736,432

MAGNETIC CLARIFIER Filed Feb. 8, 1951 4 Sheets-Sheet 2 1571 72 TJZ'ET Alfred W Garaes E7737 QM @ZVHZZHE Feb. 28, 1956 A. w. GARDES MAGNETIC CLARIFIER 4 Sheets-Sheet 3 Filed Feb. 8. 195] AZfrea N Garaes 1956 A. w. GARDES 2,736,432

MAGNETIC CLARIFIER Filed Feb. 8, 1951 4 Sheets-Sheet 4 1571 5 ZVZQT AZfreo I l/f Garaes E HZZHE Application February 8, B51, 21%;563

17 Claims. (Ci. Z'lli -LS} This invention relates to improvements in a magnetic clarifier and method of clarifying, and more particularly to a magnetic clarifier of the type embodying a plurality of pickup members movable in a tank through which flows a liquid carrying magnetic foreign particles, the invention being highly desirable for use in connection with the clarification of coolants or cutting oils used with cutting and grinding machines, although the invention may have other uses and purposes as will be apparent to one skilled in the art.

In the past, many and various types of magnetic clarification machines have been developed, wherein the intended purpose is the removal of ferrous foreign parti cles from liquid by magnetic attraction. These formerly known devices have been found objectionable in many ways. For example, they were of extremely cumbersome size, almost prohibitively expensive, not as efiicient as filtering means per se, provided no turbulence of the liquid to provide better contact with magnetic pickup members, would not pick up non-magnetic particles, and many incorporated electromagnets which of course re quired energizing. In other instances, tight fitting scrapers and other parts were employed that required frequent servicing. In every instance of which I am aware, these formerly known machines had to be shut down while the liquid tank was cleansed of accumulated sludge, and a partial take-down of a machine was necessary to clean the tank and suitable tools and instruments had to be employed for that purpose. Furthermore, machines of this character heretofore known were easily and detrimentally overloaded.

With the foregoing in mind, it is an important object of the instant invention to provide a magnetic clarifier that is only one-fourth to one-half the side of magnetic clarifiers of the same capacity heretofore known.

Another object of this invention is the provision of a magnetic clarifier that will pick up and remove both magnetic and non-magnetic foreign particles.

Still another object of the invention is the provision of a magnetic clarifier so arranged that the picked up foreign particles, referred to in the trade as swarf, forms a stationary brush which, by its action, maintains the magnetic pickup members clean and also picks up nonmagnetic particles.

A further object of the invention resides in the provision of a magnetic clarifier embodying a tank so constructed and arranged as to bring floating foreign particles close to the magnetic pickup members.

Also a feature of the invention resides in the provision of a magnetic clarifier having a liquid tank so arranged as to cause turbulation of the liquid to insure efiicient clarification of the liquid.

It is also a feature of the invention to provide a magnetic clarifier embodying a tank that is ribbed both lengthwise and crosswise to insure and cause turbulence of the liquid flowing therethrough from one end to the other and bring foreign particles into the strongest magnetic fields for removal.

Another desideratum of this invention is the provision of a magnetic clarifier so constructed that there is no need to stop operation of the clarifier while the tank is cleansed of sludge and the like.

This invention also contemplates the provision of a magnetic clarifier embodying a liquid tank that may be easily manipulated and cleansed by hand, no tools being necessary to clean the tank, and there being no securing means to adjust or fasten to hold the tank in operative position.

Another object of the invention is the provision of a magnetic clarifier so constructed as to operate efficiently at more than twice rated capacity; in other words, unless a deliberate attempt is made the clarifier cannot be over loaded detrimentally, since any excess liquid will drain out the incoming end of the clarifier and pass to the dirty liquid sump from which fluid is pumped to the clarifier.

The invention also contemplates provision of a mag netic clarifier embodying the use of permanent magnets, requiring no energization and no service.

Still another feature of the invention resides in the provision of a magnetic clarifier having an exceedingly low upkeep expense, since the structure embodies no stuffing boxes, and there are substantially no parts to get out of order.

it is also a feature of the invention to provide a magnetic clarifier embodying a simplified and easily installed gear box assembly.

The instant invention also provides an extremely economical clarifier, due to its size, construction, durability, minimum servicing, and high efficiency.

Additionally, it is an important object of the invention to provide a new and novel method of clarifying a liquid.

While some of the more salient features, characteristics and advantages or" the instant invention have been above pointed out, others will become apparent from the following disclosures, taken in conjunction with the accompanying drawings, in which- Figure l is a pictorial view of a magnetic clarifier embodying principles of the instant invention, showing the connecting pipes fragmentarily;

Figure 2 is a view similar in character to Fig. l, but taken from the opposite side of the machine;

Figure 3 is an enlarged central vertical sectional view through the clarifier, with parts shown in elevation, taken substantially as indicated by the line ill-ill of Fig. 1, looking in the direction of the arrows;

Figure 4 is a fragmentary transverse vertical sectional view taken substantially as indicated by the line IVIV of Fig. 1;

Figure 5 is a View similar in character to Fig. 4, but illustrating the machine during operation; and

Figure 6 is a plan sectional View through the gear box structure taken from the left hand end of the showing in Fig. 3.

As shown on the drawings:

While the illustrated embodiment of the instant invention is highly advantageous for use in a closed circuit embodying a single cutting, grinding, or honing machine or the like, it will be understood that the invention may be built large enough to accommodate a bank of such machines and the connections from the clarifier to each machine of the bank will be obvious to one skilled in the art. For purposes of clarity, the instant invention will, however, be described as though it were individually associated with a single cutting or grinding machine.

The illustrated embodiment of the instant invention includes a base comprising an upstanding surrounding wall 1 and an elevated bottom 2 which slopes from each end of the base toward the center as seen clearly in Fig. 3. The base thus defines a reservoir 3 for overflowing contaminated fluid in the event the machine is overloaded. From one side of the deepest portion of the reservoir 3, an outlet pipe 4 is connected through the wall of the base to drain off overflow liquid and carry this overflow liquid back to a sump for contaminated coolants or the like, not illustrated in the drawings, and from which contaminated liquid is pumped to the clarifying apparatus.

Secured to the bottom 2 inside the reservoir 3 adjacent an end thereof in any suitable manner is an upstanding frame member 5, and as seen clearly in Fig. 3 this frame member is inclined from the vertical toward the opposite end of the reservoir. With reference to Figs. 2 and 3 it will be seen that a subframe portion 6 of the frame functions as a suitable support for an electric motor 7 energized from any available convenience outlet. Inside the motor mounting 6, the frame 5 is shaped to form a housing 8 for gearing that will later be described herein, this housing being normally closed by a removable cover 9.

Secured to the bottom 2 adjacent the other end of the reservoir 3 is another upright structure it) shaped to define a clarified liquid receiver 11 having an outlet opening 12 in the lower portion of the outside wall thereof from which a pipe 13 carries the clarified liquid back to the cutting or grinding machine. The inside wall of the receiver 11 is notched out as indicated at 14 in Pig. 3 in weir-like manner to afford an inlet for clarified liquid. At the upper end thereof the outer wall of the receiver 11 is provided with an outwardly and downwardly sloping bearing mounting 15.

A rotatable shaft 16 is journaled in the aforesaid bearing mounting 15 and also in the inside wall portion of the gear housing 8 on the aforesaid standard or frame member 5. As so mounted, the shaft is downwardly inclined from the frame member 5 toward the bearing mounting 15. This downward inclination of the shaft 16 eliminates any need for expensive stufling boxes or glands.

Rotatable therewith and carried substantially centrally on the shaft 16 is a magnetic pickup assembly generally indicated by numeral 17, to be later described. This magnetic pickup assembly 17 rotates partially within a removable tank 18 to which contaminated fluid is admitted at one end through a fan-shaped nozzle generally indicated by numeral 19 and bolted or otherwise secured to the top of the standard 5. As seen in Figs. 1 and 2, a pipe 20 is connected to an intake opening 21 (Fig. 3) to the nozzle, and through this pipe 20 contaminated fluid is pumped from a suitable sump.

The fluid tank 18 is preferably a casting of aluminum or other lightweight non-magnetic material. With reference now to Figs. 1, 3 and 4, it will be seen that this tank is open-topped, and substantially centrally thereof the wall is provided with a reentrant angular portion 22 in both side walls and the bottom. This reentrant wall portion provides an interior baflie to cause a turbulence of the liquid flowing through the tank. At the front end thereof, the tank is notched as indicated at 23, Fig. 3, in the upper end wall portion, which notch may be substantially three times the diameter of the shaft 16 in width, or, if desired, even a little wider. On each side of the notch the front wall of the tank is provided with an angular supporting bracket 24 bolted or equivalently secured to the tank. These supporting bracket each engage freely over a lip 25 integral with the adjacent wall of the inlet nozzle 19.

The opposite end Wall of the tank 18 is also provided with a notch-like indentation 26 lipped as indicated at 27 to freely engage over the notch 14 in the inner Wall of the receiver 11. Thus, the shaft 16 does not in any manner contact the tank 18, although the walls of the tank extend upwardly on each side of the shaft. It is a simple expedient, therefore, to raise the lip 27 out of engagement with the adjacent wall of the receiver 11, moved the tank 4 bodily to the left a viewed in Fig. 3 until the brackets 24 clear the lips 25, lower the tank and remove it completely from the machine. The tank may be easily replaced by reversing the process, there being no securing means to tighten or fasten in order to hold the tank in operative position.

While the reentrant baffle of rib 22 prevents vertical stratification of the flowing liquid, liquid over a relatively wide area will tend to laterally stratify as well. That is, a portion of the liquid will flow faster than another portion. To offset such occurrence, the bottom of the pan is provided with a pair of spaced upright ribs 2828, which are identical and extend between the recessed or notched end portions 23 and 26 of the tank. As seen in Fig. 3, these ribs are relatively deeply notched at various points therealong to come close to but not contact the rotating pickup assembly 17. The ribs 23-28, as seen in Fig. 4, divide the bottom portion of the tank into three lengthwise channels which are sufficiently narrow to prevent lateral stratification of the flowing liquid.

In order to still further insure proper and even flow of all the liquid passing through the tank 18, it will be seen in Figs. 3 and 4 that the fan-like inlet nozzle 19 is provided with three spaced inverted U-shaped partitions, 29, 3t and 31. Each such partition defines an open notch in the nozzle. The partitions 29 and 31 extend over or embrace adjacent portions of the ribs 28-23, while the central and larger partition 30 loosely embraces the shaft 16. Thus, there are four separate outlets from the nozzle, a relatively wide outlet 32 into one side channel of the tank, a similar outlet 33 into the opposite side channel of the tank, and a pair of smaller outlets 34-34 into the central channel. In Fig. 3 I have indicated by a dash line 35 the normal level of liquid flowing through the tank 18, and it will be noted that this normal liquid level is above the outlet opening of the nozzle 19, so that the incoming liquid is discharged below the normal liquid level to avoid splashing.

The illustrated embodiment of the magnetic pickup assembly 17 is best seen in Fig. 3. This assembly embodies in effect three magnetic pickup rings including an end magnetic disk or ring 36, a pair of centrally located disks of lesser diameter 37 and 38, and an opposite end disk or ring 39. The two center disks 37 and 38, by virtue of their juxtaposed relationship, function as one pickup disk in operation, which is magnetically stronger than either of the end disks 36 and 39 by virtue of its in creased thickness. Between each pair of adjacent disks is a ring magnet 41), preferably a long lived permanent magnet, the ends of the ring magnet being seated in annular grooves in the confronting pickup disks as indicated at 41. Outside each ring magnet is a shell or cylinder 42 of non-magnetic material, such as brass, similarly seated in annular grooves in the confronting pickup disks. The entire assembly is held in proper position on the shaft 16 by means of a non-magnetic retainer bushing 43 seated in a central aperture in each of the pickup rings or disks 36, 37, 38, and 39, the inside retainer bushings being disposed oppositely to the outside ones, and

each retainer bushing being so shaped as to provide in effect an annular rebated joint with its respective disk. At one end of the assembly is a snap ring 44 secured in a groove in the shaft 16, while at the other end of the assembly is a nut 45 threaded on the shaft, and secured in place by means of a jamb nut 46. Thus the entire assembly is firmly anchored on the shaft 16.

At this point, it may be Well to mention that the inlet nozzle 19 preferably cast from non-magnetic metal such as aluminum, the tank 18 is non-magnetic, the shaft 16 is preferably stainless steel of the non-magnetic type, and the shells or cylinders 42 and bushings 43 are non-magnetic. This leaves only the permanent magnets 40- 1%) and the pickup disks 36, 3'7, 38, and 39 of magnetic material. The nuts 45 and 46 are preferably non-magnetic, and it makes no difference whether the snap ring 44 is magnetic or not by virtue of its disposition. With this arrangement, the magnetic flux is concentrated at the outermarginal portions of the pickup rings.

From the showing in Fig. 3, it will be seen that the pickup rings enter into the respective notches in the lengthwise-ribs 28- 28 of the tank 18 so that substantially all the-magnetic particles carried by the fluid passing throu the tank are brought into the magnetic field of one or the other of the pickup rings.

The drive means for the shaft 16 are best seen in Figs. 3 and'6, the latter figure being a plan sectional view through'the worm assembly. A worm wheel 47 is keyed 'to 'the end of shaft 16 inside the aforesaid gear housing 'S'inthe standard 5. Cast integrally with a portion of thisstandard is apair of spaced outwardly extending lugs 48 and 49. These lugs are both transversely bored to support atshaft 50 carrying a worm 51 in mesh with the worm wheel 47.

One end of the shaft 50 is journaled in the bore of the bracket 49 and'the bore is closed by means of a suitable mo'torzshaft.

It will be noted that with this assembly, it is a simple expedientto remove'the cover assembly 57, and the entire worm and shaft assembly may be withdrawn as a unit through the bore in the bracket 48, thus greatly facilitating assembly of the gearing. The gearing, of course, is reduction gearing so that the shaft 16 is driven at a far slower speed than that of the motor.

As the magnetic pickup assembly 17 rotates inside the fluid in the tank 18, foreign particles are picked up out sofsthe fluid by magnetic attraction, adhere to the pickup rings 3'6, 37, :38, and 39, and are discharged therefrom down a chute 59 bolted or equivalently secured to a fixed bar- 60 extending between the uprights 5 and lit on one side of the machine. Thechute is notched at the pickup :end thereof to provide projecting portions 61 extending between the pickup rings of the assembly 17. As will more fully appear later herein, it is not essential that the 'fingers -or extensions 61 intimately contact the pickup rin'gs orthe brasscylinders 42 therebetween with a positive scraping contact. In fact, the side edges of the fingers =161 may Ibe as much -as & inch away from the adjacent pickup rings 'without interfering with the eflicient opera- .ition ofzt'hemachine. If so desired, opposed springs 6262 attached t'o'th'e bottom 2 of the base may be hooked over the sides of'the chute 59 to urge the pickup end of this (chute down into contact with the brass cylinders 42-42 to insure the discharged chute remaining in proper position-during operation and to facilitate the operation of the machine at the start.

In operation, the instant invention is extremely simple .and highly efficient. Contaminated fluid is pumped into "the tank 18 through the nozzle 1), passes tirough the tankiand flows over the notched portion 26 into the clean fluid receiver 1 1 from which it is pumped back to the cutting or grinding machine. After being used at the machine, .and again becoming contaminated, the fluid returns toa sump from which it is again pumped to the clarifying apparatus. The circulation is continuous.

It-will be especially noted that by virtue of the transverse rib or baflle 22, and the longitudinal ribs 2$28 in the tank, a turbu'lence is set up in the fluid as it passes through the tank, and all foreign particles in the fluid are thereby brought into intimate association with the strongest magnetic fields of the respective pickup rings '36, 37,38, and 39. It is obvious that if under special circumstances more'pickup rings are desired, it is a simple expedient to make the structure somewhat larger as to the tank, and to lengthen the pickup assembly 17 by adding one or more magnets in an obvious manner. Further, the shape of the tank, with the top closer to the pickup members than the bottom, insures the gathering'of float.

The instant machine has a very peculiar action in its removal of foreign particles from the contaminated fluid. With reference now to Fig. 5, it will be seen that these particles are retained by the magnets sufllcientlytobuild up relatively high and thick brushes of swarf as indicated at 63 around the pickup rings, and partially on the brass cylinders 42-42 therebetween. The swarf or removed impurities is gradually urged rearwardly on the discharge chute 59, until it reaches the inclined portion thereof when it discharges by gravity into any suitable receptacle. The formation of the brush effect 63 is built up on the magnets far ahead of the edge of the pickup chute 59 as illustrated. The brush particles closest to the ring magnets illill are maintained concentrated and function to wipe the pickup rings 36, 3'7, 33, and 39 and maintain these rings in a clean condition after passing by the edge of the chute 5%, as seen in Fig. 5. This utilization of removed foreign particles as a wiping medium for the pickup rings provides a new and unexpected result. It not only eliminates the necessity of scraping magnetic particles from the pickup rings as was heretofore done, but it also enables non-magnetic particles to be picked up by coming in contact with the brush-like accumulation of magnetic particles, so that substantially all non-magnetic particles are also removed from the contaminated fluid.

t should also be noted that many magnetic and nonmagnetic particles will be of suflicient fineness and lightness as to float on the contaminated fluid in the tank 18, and the construction of the tank as above pointed out brings this float into close proximity with the pickup rings, whereupon substantially all of the float will adhere to the pickup rings until it is removed therefrom by the brush-like accumulation 63 and will remain attached to these accumulations.

With reference again to Fig. 3, it will also be especially noted that should the machine for any reason become overloaded with contaminated fluid, the excess fluid will flow out of the tank 18 at the incoming end thereof through the notched portion 25 and descend into the reservoir 3 in the base whereupon it will flow through the outlet pipe 4 back to the contaminated liquid sump. Thus, even a relatively great overloading of the machine will not adversely affect the efficiency of the machine or do any damage whatever, there being a continuous supply of cleaned fluid returning to the cutting or grinding machine.

It is also quite apparent that there is little servicing required to any part of the clarifying device. At infrequent intervals, the tank 1'8 should be removed and emptied of accumulated sludge. This operation may be performed quickly and by hand and there is no necessity to stop the operation of the clarifier while the tank is being cleaned. it is a simple expedient to elevate the tank until the lip 27 clears the adjacent wall of the receiver it, slip the brackets 24 off the adjacent lips 25 of the intake nozzle 19, quickly dump the tank, and replace it in position. This operation may be performed so simply and so rapidly that the supply of fluid to the cutting or grinding machine will not be noticeably interrupted, the supply of fluid in the clean fluid receiver 11 being suflicient to maintain a supply to the cutting or grinding machine.

The instant machine is extremely small in size for its relatively high capacity. For example, it may be mentioned that a machine embodying a tank 18 of a maximum top length of approximately eleven inches, a maximum depth at the incoming end not exceeding five inches, and a width of approximately seven inches, will easily operate at a fluid capacity of twenty gallons per minute, and will produce substantially the same high efliciency at a 100% overload with a comparatively small amount of liquid flowing into the reservoir 3 in the base. Even an overload in excess of 100% will not detrimentally impair the efficiency or operation of the machine.

It is believed that my novel method, incorporating the highly important step of utilizing removed foreign partticles to effect further cleansing, is suliiciently apparent from the foregoing as to warrant no further description herein.

It will be understood that modifications and variations may be elfected without departing from the scope of the novel concepts of the present invention.

1 claim as my invention:

1. In a magnetic clarifier, a tank for flowing liquid, means to deliver contaminated fluid into one end of said tank, spaced ribs extending inwardly from the wall of said tank to cause turbulence in the fluid, rotary magnetized pickup means movable in said tank, certain of said ribs having notches therein, and said pickup means including outwardly extending magnetized members passing through said notches.

2. In a magnetic clarifier, a tank for flowing liquid,

spaced upstanding longitudinal ribs on the bottom of said tank dividing said bottom into a plurality of separate paths, liquid inlet means having separate discharge orifices for said paths extending into one end of said tank, and a single rotary magnetized pickup drum extending into both said paths.

3. In a magnetic clarifier, a tank for flowing liquid, spaced upstanding longitudinal ribs on the bottom of said tank dividing said bottom into a plurality of separate paths, a fan-shaped nozzle extending into said tank to deliver contaminated liquid, said nozzle being notched to extend over said ribs and partitioned to provide separate outlets for said paths, and a rotary magnetized pickup drum movable in said tank in both said paths.

4. In a magnetic clarifier, an upstanding reservoir for clarified liquid, a tank for flowing liquid, said reservoir having an inner wall, an outflow lip on said tank resting freely on said inner Wall, a nozzle to deliver contaminated liquid to said tank, the adjacent end of said tank being freely suspended from said nozzle, a reservoir be neath said tank for any overflow of contaminated liquid, and rotary magnetized pickup means movable in said tank.

5. In a magnetic clarifier, an upstanding reservoir for clarified liquid, a tank for flowing liquid, said reservoir having an inner wall, an outflow lip on said tank resting freely on said inner wall, stationary means adjacent the other end of said tank, supporting lugs on said means, holding means on said tank freely resting on said lugs whereby said tank is readily removable, means to deliver contaminated liquid to said tank, and rotary magnetized pickup means movable in said tank.

6. In a magnetic clarifier, a rotary pickup drum, a plurality of coaxial magnetized pickup members of different diameters in said drum, a tank for flowing liquid underneath said assembly and into which said assembly extends, means to deliver contaminated liquid to said tank, and internal inwardly extending ribs carried by the Walls of said tank to bring floating and submerged foreign particles adjacent said pickup members, certain of said ribs being notched at various depths to accommodate said pickup members.

7. A magnetic pickup assembly for a magnetic clarifier, including a shaft, a permanent ring magnet concentric with said shaft, magnetic pickup discs secured to said shaft and each having an annular groove in a side face thereof receiving an end of said ring magnet, and a nonmagnetic cylinder concentric to the magnet and also set into the confronting faces of said discs outside said ring magnet, the outside diameter of said cylinder being less than that of said discs.

8. A magnetic pickup assembly for a magnetic clarifier, including a shaft, a non-magnetic cylindrical shell concentric with but spaced from said shaft, disc-like magnetic pickup members secured to said shaft at each end of said shell but of greater diameter than said shell, and a permanent ring magnet inside said shell around said shaft with its ends in contact with said pickup members.

9. A magnetic pickup assembly for a magnetic clarifier, including a non-magnetic shaft, spaced non-magnetic bushings fixed to said shaft, magnetic discs surrounding and fixed to said bushings, a permanent ring magnet concentric with but spaced from said shaft with its ends in contact with the inner faces of said discs, and a nonmagnetic shell concentric with but spaced outwardly from said magnet in contact with said discs and of less diameter than said discs.

10. A magnetic pickup assembly for a magnetic clarifier, including a non-magnetic shaft, spaced non-magnetic bushings fixed to said shaft, magnetic discs surrounding and fixed to said bushings, a permanent ring magnet concentric with but spaced from said shaft with its ends'in contact with the inner faces of said discs, a non-magnetic shell concentric with but spaced outwardly from said magnet and of less diameter than said discs, said discs each having concentric annular grooves in the inner face thereof into which the ends of said magnet and said shell are seated, and means outside said discs on said shaft to hold the assembly together.

11. In a magnetic clarifier, a tank for flowing liquid, means to deliver contaminated liquid to said tank, a rotary drum-like pickup assembly extending into said tank, axially spaced disc-like magnetized elements on said assembly, and one of said elements possessing a stronger magnetic attraction than any other, there being at least one weaker element between said stronger element and said liquid delivery means.

12. In a magnetic clarifier, a tank for flowing liquid, means to deliver contaminated liquid to said tank, a rotary drum-like pickup assembly extending into said tank, axially spaced outstanding annular magnetized members on said assembly, one of said members being magnetically stronger and of less diameter than any other member, and a transverse inwardly extending rib on said tank opposite said one member to cause turbulence in the flowing liquid and bring foreign particles close to the magnetic field of said one member.

13. In a magnetic clarifier, a rotary pickup assembly including non-magnetic drum-like means, a plurality of magnetic pickup discs spaced along said means and of greater diameter than said means, means to magnetize said pickup discs, a tank through which liquid flows in the direction of the axis of said assembly and in which said assembly rotates, spaced upwardly extending ribs running lengthwise of the bottom of said tank, said ribs being notched to accommodate said pickup discs, and means to deliver contaminated liquid to said tank.

14. In a magnetic clarifier, a tank through which liquid may flow, means to deliver contaminated liquid to said tank, a rotary pickup assembly extending into said tank, a plurality of spaced outstanding completely annular magnetized pickup members on said assembly, nonmagnetic means of lesser diameter than said members and separating said members, a chute for removed foreign particles having a receiving end in proximity to an exposed part of said assembly, and the magnetic fields of said members being of suflicient strength to cause removed particles to continuously pile up adjacent the end of said chute in brush-like manner and wipe off non-magnetic particles adhering to said assembly.

15. In a magnetic clarifier, a tank through which liquid flows from one end to the other, a rotary drum-like pickup assembly extending into said tank and having its axis lengthwise of the tank parallel with the direction of liquid flow, said assembly including spaced magnetizable discs, a permanent ring magnet between each pair of discs with its ends in abutment with the discs, said ring magnet being of less diameter than said discs, and a non-magnetic cylinder concentric with but of greater diameter than the ring magnet between each pair of discs with its ends also abutting the discs.

16. In a magnetic clarifier, a tank through which liquid flows from one end to the other, a rotary drum-like pickup assembly extending into said tank and having its axis lengthwise of the tank parallel with the direction of liquid flow, said assembly including spaced magnetizable discs, a permanent ring magnet between each pair of discs with its ends in abutment with the discs, said ring magnet being of less diameter than said discs, and a non-magnetic cylinder concentric with but of greater diameter than the ring magnet between each pair of discs with its ends also abutting the discs, there being at least two pairs of said discs with one disc of each pair in face-to-face abutment with a disc of the other pair.

17. In a magnetic clarifier, a tank through which liquid flows from one end to the other, a shaft extending lengthwise of said tank parallel with the direction of liquid flow, a rotary drum-like pickup assembly on said shaft to rotate therewith, said assembly including two pair of magnetizable discs with the discs of each pair spaced along said shaft but with the inner discs of said pairs in face-to-face abutment, a ring magnet of less diameter than said discs between each pair of discs with its ends in abutment with the respective discs, a non-magnetic cylinder between the discs of each pair with its ends abutting the respective discs, said cylinders being concentric with but of greater diameter than said ring magnets, and means to maintain the magnets and cylinders in tight endwise abutment with the discs.

References Cited in the file of this patent UNITED STATES PATENTS 69,128 Righter Sept. 24, 1867 914,696 Briney Mar. 9, 1909 1,617,971 Ullrich Feb. 15, 1927 2,094,615 Parker Oct. 5, 1937 2,149,764 Frei Mar. 7, 1939 2,191,962 Jones Feb. 27, 1940 2,272,719 Maynard Feb. 10, 1942 2,326,575 Stearns Aug. 10, 1943 2,459,343 Scrivener Jan. 18, 1949 2,541,202 Caldwell Feb. 13, 1951 2,564,593 Caldwell Aug. 14, 1951 2,597,561 Blind May 20, 1952 FOREIGN PATENTS 194,107 Great Britain Mar. 8, 1923 272,784 Great Britain June 23, 1927 557,214 Great Britain Nov. 10, 1943 

1. IN A MAGNETIC CLARIFIER, A TANK FOR FLOWING LIQUID, MEANS TO DELIVER CONTAMINATED FLUID INTO ONE END OF SAID TANK, SPACED RIBS EXTENDING INWARDLY FROM THE WALL OF SAID TANK TO CAUSE TURBULENCE IN THE FLUID, ROTARY MAGNETIZED PICKUP MEANS MOVABLE IN SAID TANK, CERTAIN OF SAID RIBS HAVING NOTCHES THEREIN, AND SAID PICKUP MEANS INCLUDING OUTWARDLY EXTENDING MAGNETIZED MEMBERS PASSING THROUGH SAID NOTCHES. 